We have developed a variety of tasks to activate regions of interest in functional neuroimaging studies. 1. To examine the distinction between recall and familiarity in episodic memory function we have developed a task using visual scenes that reliably induces familiarity based errors in controls. 2. We assessed the role of COMT genotype in an fMRI event related study which gauged the effects of cogntive control on various conditions involving interference in the so called flanker task. 3. We developed a carefully matched set of verbal fluency tasks to examine the relation between semantic processing, thought disorder, and neurophysiology in schizophrenia using PET CBF methods. We found an area in inferior prefrontal cortex that was more activated in semantic fluency and correlated with a classic symptom of schizophrenia -- thought disorder.